SAN Training – Day1

Agenda

Introduction to SAN

DAS

NAS

SAN

RAID Technologies

CIFS

NFS

ISCSI

FCP

FCIP

Snapshot

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Why we will go for SAN?

In DAS HDDs are connected in a single path and bandwidth also shared.

SCSI cable length is max. 25 meter and can connect max. 16 disks

Maintenance down time is there

Application needs performance

Scalability

Difficult backup management

Inaccessible to data during maintenance

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I/O channel scsi I/O channel (Ethernet) I/O Channel (FC)

Few devices connected Many Devices connected Many devices 16 Million

Static (One to one) (can’t

attaché another server

Dynamic Plug and play Dynamic

Low latency High latency Low latency Micro second

Short distance 25 meter Longer distance Long distance 1000KM

Hardware based delivery

management (Block level)

Software based delivery

management (TCP/IP)

Hardware based delivery

management (Block level)

Why we will go for SAN?

Storage Area Network

What is Storage Area Network?

Storage Area Network (SAN) is a specialized, high speed, high availability network that

uses fiber channel technology to connect servers to storage disks.

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Common SAN Definitions

Node -Any device connected to the SAN (servers, Tap drives, Tape library, VMware

server, Unix server etc.…)

WWN (world wide Name)-Unique identifiers used to identify storage devices

Fabric-Encompasses all hardware that connects servers and workstations to storage

devices through the use of fiber channel switching technology

Fiber Channel-High speed network technology used mainly for the storage area

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Design Considerations

Should solve an underlying business need.

Meet business requirements for availability and reliability

Be scalable to meet current and future business needs

Be cost-effective and easy of manageability

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Benefits of a SAN

Eliminates restrictions on the amount of data that can be accessed by an individual

server as oppose to server with direct attached disk.

Storage can be accessed by multiple serves simultaneously with faster processing.

Storage resources can be centrally managed and storage space can be allocated and

deallocated to hosts as needed.

Components are hot-swappable, eliminating downtime

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Three Basic Forms of Network Storage

Direct access storage (DAS)

Network attached storage (NAS)

Storage area network (SAN)

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What is Direct Attached Storage (DAS)?

Direct Attached Storage (DAS), the name is pretty

self-explanatory. A disk subsystem that is directly

connected to a host rather than going through a

switched network, thereby giving the host

exclusive access to the disks.

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Network Attached Storage (NAS)

Specialized storage device or group of storage devices providing centralized fault-

tolerant data storage for a network

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SAN

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Fabric

Quick Overview

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RAID (Redundant Array of Independent Disks)

A group of hard disks is called a disk array

RAID combines a disk array into a single virtual device called RAID drive

Provide fault tolerance for shared data and applications

Different implementations: Level 0-5

Characteristics:– Storage Capacity– Speed: Fast Read and/or Fast Write (Performance)– Resilience in the face of device failure (Fault tolerance)

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RAID LEVELS

RAID 0 – striping (Min-2 and Max-16)

RAID 1 – mirroring (Min-2 and Max-2)

RAID 5 – striping with parity(Min-3, max-16)

RAID 6 – striping with double parity (Min-4, Max-16)

RAID 10 – combining mirroring and striping (Min-2, Max-16)

RAID DP & 4 - This is only for NetApp

RAID level 0 – Striping

In a RAID 0 system data are split up in blocks

that get written across all the drives in the array.

By using multiple disks (at least 2) at the same

time, this offers superior I/O performance

RAID level 1 – Mirroring

Data are stored twice by writing them to both the

data drive (or set of data drives) and a mirror drive

(or set of drives) . If a drive fails, the controller uses

either the data drive or the mirror drive for data

recovery and continues operation. You need at least

2 drives for a RAID 1 array.

RAID level 5

RAID 5 is the most common secure RAID level. It requires

at least 3 drives but can work with up to 16. Data blocks

are striped across the drives and on one drive a parity

checksum of all the block data is written. The parity data

are not written to a fixed drive, they are spread across all

drives, as the drawing below shows. Using the parity data,

the computer can recalculate the data of one of the other

data blocks, should those data no longer be available.

That means a RAID 5 array can withstand a single drive

failure without losing data or access to data. Although

RAID 5 can be achieved in software, a hardware controller

is recommended. Often extra cache memory is used on

these controllers to improve the write performance.

RAID level 10 – combining RAID 1 & RAID 0

It is possible to combine the advantages (and

disadvantages) of RAID 0 and RAID 1 in one single

system. This is a nested or hybrid RAID

configuration. It provides security by mirroring all

data on secondary drives while using striping across

each set of drives to speed up data transfers.

For more random access we can go for this raid and

EMC called this raid as fastest raid.

Mirroring + Striping (Gives highest performance as

there is no calculation happening)

RAID-4 and RAID-DP

RAID4-To implement Raid-4 minimum 3 disks required and It can sustain one disk failure. It is a horizontal row parity approach.

Raid-DP-To implement Raid-DP minimum 4 disks required and it can sustain 2 disks failure. It is a diagonal parity stripe

CIFS

CIFS (Common Internet File system)

CIFS, a protocol that defines a standard for remote file access using millions of

computers at a time. With CIFS, users with different platforms and computers can share

files without having to install new software.

CIFS runs over TCP/IP but uses the SMB (Server Message Block)protocol found in

Microsoft Windows for file and printer access.

Configure and access the CIFS share

Configure the CIFS and start SMB protocol in NetApp storage

Create CIFS share

Access and create CIFS share from windows client

Map a network drive for windows client

Edit permission for CIFS share

Configure CIFS share

Configure CIFS share

Configure CIFS share

NFS

NFS file system

NFS is Unix file system developed by the Sun-microsystem through which we can access the

share drive or volume from the storage to Unix machines.

Configure and access NFS

Objectives-:

Understand Unix file system

Configure the NFS exports in NetApp stooge

Mount NFS exports to a Unix/Linux client machine

Create and delete the files from the client machine

NFS

NFS

NFS

NFS

NFS

NFS

iSCSI (internet scsi)

Hardware iscsi (Iscsi hba)

TOE + ISCSI Headers

-TCP offload engine –it is processing the TCP/IP header

Data going as block through the network called SAN

Fiber Channel Protocol

FC (Fibre Channel) is just the underlying transport layer that SANs use to transmit data.

This is the language used by the HBAs, hubs, switches and storage controllers in a SAN to

talk to each other. The Fibre Channel protocol is a low-level language meaning that it's

just used as a language between the actual hardware, not the applications running on it.

Fiber Channel Protocol

FCOE (FC Over Ethernet)

FCIP(Fiber channel over IP)

NETAPP SNAPSHOT TECHNOLOGY

How does NetApp snapshot technology works?

When data ontap creates a snapshot copy, it preserves the inode map as it is at the point

in time and then continuous to make changes to the inode map on the active file system.

Data ontap keeps the older version of the inode map.

There is no data movement at the point in time of the snapshot copy is created.

NETAPP SNAPSHOT TECHNOLOGY

NETAPP SNAPSHOT TECHNOLOGY

NETAPP SNAPSHOT TECHNOLOGY

NETAPP SNAPSHOT TECHNOLOGY

NETAPP SNAPSHOT TECHNOLOGY

SNAPSHOT COPIES :-

We can create 255 snapshots per volume

Point in time copy

Created in a few seconds

No performance penalty

Snapshot in other SANs

Snapshot in other SANs

Snapshot in other SANs

Thanks!